CN117595449A - Charging and discharging control device, charging control method and discharging control method - Google Patents

Abstract

The invention discloses a charge and discharge control device, a charge control method and a discharge control method. The device comprises a control module and at least two charge-discharge modules which are connected in series, wherein each charge-discharge module comprises a charge-discharge switch and a bypass module. The control module monitors all of the batteries. When one battery is fully charged and the other batteries are not fully charged during charging, the corresponding charging and discharging switch is closed to stop charging, and the corresponding bypass module is opened to continue charging the other batteries. When all batteries are full, all bypass modules and charge and discharge switches are closed, so that the whole battery pack is in a true full-charge state. When discharging, when the sum of voltages of all batteries connected in series is higher than the upper limit of load voltage, a certain number of batteries connected in series are selected to reach the load voltage range, and different batteries are alternately replaced to supply power to the load, so that the voltage and the electric quantity of each battery are not greatly different. When the sum of all the battery voltages does not exceed the upper output limit, the charge and discharge switches are simultaneously turned on, and the bypass module is simultaneously turned off.

Description

Charging and discharging control device, charging control method and discharging control method

Technical Field

The present invention relates to the field of charge and discharge technologies, and in particular, to a charge and discharge control device, a charge control method, and a discharge control method.

Background

In recent years, new battery technology is continuously emerging, and the working voltage of some batteries is wider, for example, the working voltage range of a sodium ion battery is between 1.5V and 4.0V, and if the battery is directly used for replacing a lithium battery or a lead-acid battery, only about 50% of the electric quantity can be discharged. In addition, the operating voltage ranges of different batteries are mostly different, and the discharging voltage ranges cannot be completely matched when the batteries are replaced. In order to realize that different batteries are mutually replaced to realize ideal discharge voltage interval matching, the advantages of the batteries with the same wide working voltage as the sodium ion battery are fully exerted, and the stored electric quantity of the batteries can be fully discharged, therefore, the batteries are randomly switched in series, but in the realization process, at least the following problems in the prior art are not solved: the DC-DC conversion circuit has the problems of high cost, poor transient discharge capability and relatively high fault rate; 2. the single battery is used as a switching object, and the problems of complex system, high cost, low efficiency, high failure rate and poor anti-interference capability are solved; 3. the battery pack switching has the problems of larger limit of working voltage range, complex perfect matching system and high cost. 4. The conventional series battery pack can be charged only in its entirety, and the charging is disconnected when the entirety is charged, but there is a possibility that a part of the batteries in the middle is not charged.

Disclosure of Invention

The invention aims to provide a charge and discharge control device, a charge control method and a discharge control method, which can disconnect a fully charged battery and continuously charge an uncharged battery so as to enable the whole series battery pack to achieve a real full-charge state.

In order to solve the technical problems, the invention adopts the following technical scheme:

an aspect of the embodiment of the present invention provides a charge and discharge control device, where the charge and discharge control device includes a control module and at least two serially connected charge and discharge modules, the control module is electrically connected with the at least two serially connected charge and discharge modules, and the charge and discharge modules each include: the battery charging and discharging device comprises a charging and discharging switch and a bypass module, wherein a first end of the charging and discharging switch is used for being electrically connected with a negative electrode of a battery, a second end of the charging and discharging switch and a first end of the bypass module are used for being electrically connected with a negative electrode of a charging power supply or a next charging and discharging module, and a second end of the bypass module is used for being electrically connected with a positive electrode of the battery and a positive electrode of the charging power supply or a last charging and discharging module; the control module is used for detecting the electric signals of one or more batteries, controlling the on-off of one or more charge-discharge switches and controlling the on-off of one or more bypass modules.

In some embodiments, the charge-discharge control device further includes a charge master switch, a first end of the charge master switch is electrically connected to the battery anodes of the at least two serially connected charge-discharge module heads, and a second end of the charge master switch is electrically connected to the anode of the charge power supply.

In some embodiments, the bypass module comprises a first diode, wherein the positive electrode of the first diode and the second end of the charge-discharge switch are used for being electrically connected with the negative electrode of a charging power supply or electrically connected with the next charge-discharge module; the negative electrode of the first diode is used for being electrically connected with the positive electrode of the battery and the positive electrode of the charging power supply or the last charging and discharging module.

In some embodiments, the bypass module further comprises a bypass switch connected in parallel with the first diode, and the control module controls the bypass switch to be turned on and off.

In some embodiments, the bypass switch employs a relay or a triode.

In some embodiments, the bypass module employs a MOSFET or load switch or relay or ideal diode.

In some embodiments, the charge-discharge switch employs a relay or MOSFET or triode or load switch.

In some embodiments, the charge-discharge module further comprises a fuse in series with the battery, the charge-discharge switch.

In some embodiments, the charge-discharge control device further includes a buffer circuit, the buffer circuit includes a resistor and a super capacitor, one end of the resistor is electrically connected with the positive poles of the batteries at the heads of the at least two serially connected charge-discharge modules, the other end of the resistor is electrically connected with the positive poles of the super capacitor, the negative pole of the super capacitor is electrically connected with the negative poles of the batteries at the tails of the at least two serially connected charge-discharge modules and the negative pole of the load, and the other end of the resistor is used for outputting positive power to the positive poles of the load.

In some embodiments, the charge-discharge control device further comprises a buffer circuit, the buffer circuit comprises an inductor, one end of the inductor is electrically connected with the battery anodes of the heads of the at least two serially connected charge-discharge modules, and the other end of the inductor is used for outputting an anode power supply to the anode of the load.

In some embodiments, the buffer circuit further comprises a flywheel diode, wherein the negative electrode of the flywheel diode is electrically connected with one end of the inductor, and the positive electrode of the flywheel diode is used for electrically connecting the negative electrodes of the batteries at the tail parts of the at least two serially connected charge-discharge modules and the negative electrode of the load.

In some embodiments, the charge master switch employs a relay or triode or MOSFET or load switch.

An aspect of an embodiment of the present invention provides a charge control method applied to a charge and discharge control device as described above, including: step 101, detecting and acquiring electric signals of all batteries in at least two serially connected charge and discharge modules; 102, when the electric signals of all batteries in at least two serially connected charge-discharge modules are lower than a first preset threshold value, controlling the charge main switch and all charge-discharge switches to be turned on and controlling all bypass modules to be turned off; step 103, when the electric signal charge of one of the batteries reaches a second preset threshold, the charge-discharge switch corresponding to the battery which controls the electric signal to reach the second preset threshold is turned off, and the bypass module corresponding to the battery which controls the electric signal to reach the second preset threshold is turned on; and 104, when the electric signals of all batteries in the at least two serially connected charge and discharge modules reach a second preset threshold value, controlling the charge main switch to be disconnected and controlling all bypass modules to be disconnected.

An aspect of an embodiment of the present invention provides a discharge control method, applied to a charge-discharge control device as described above, including: step 201, acquiring a power supply voltage interval of a load, acquiring electric signals of all batteries in the at least two serially connected charge-discharge modules, calculating to obtain a set number of batteries in the at least two serially connected charge-discharge modules according to an upper limit value of the power supply voltage interval and the electric signals of all batteries, and serially connecting the batteries to the set number according to the order of the electric signals from high to low, and then supplying power to the load; step 202, switching the batteries in the set number from low to high according to the sequence of the electric signals and the batteries outside the set number from high to low according to the sequence of the electric signals; and step 203, stopping switching when the electrical signal of the series connection of the batteries with the set number is lower than the electrical signal difference value between the upper limit value of the power supply voltage interval and the battery with the highest voltage among the batteries with the set number, and entering step 201 until the series connection number of the batteries with the set number is all the batteries in the at least two series connection charge and discharge modules.

In some embodiments, after step 203, the method further comprises: step 204, when the electrical signal of a single battery in the at least two serially connected charge-discharge modules is lower than a third preset threshold value, disconnecting a charge-discharge switch corresponding to the battery with the electrical signal lower than the third preset threshold value, and connecting a corresponding bypass module; and 205, when the electric signals of all the batteries in the at least two serially connected charge-discharge modules are lower than the lower limit value of the power supply voltage interval, controlling the at least two serially connected charge-discharge modules to stop supplying power to the load.

According to the charge and discharge control device, the charge control method and the discharge control method provided by the embodiment of the invention, the charge and discharge control device has at least the following beneficial effects: the method and the device can disconnect the fully charged battery, and charge the battery which is not fully charged continuously, so that the whole series battery pack achieves a real full-charge state. When the power supply module supplies power to a load, the serial individual and the number of the batteries in the power supply module can be changed, the range requirement on the voltage range of the serial charge and discharge module is greatly reduced under the requirement of ensuring the range of the output voltage, the suitability of the overall output voltage of the serial charge and discharge module is improved, the output current under the same output power is reduced, and the power consumption can be reduced. The power supply module can be automatically switched, and the potential of the battery in each power supply module can be released to the greatest extent. The system has the advantages of simple structure, advanced performance, low failure rate and strong anti-interference capability, and has good adaptability to substitution and compatibility of different types of battery systems. The solution is almost applicable to all the chemical batteries known in the prior art, and is a technical solution which is greatly superior to the prior art.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic circuit diagram of one embodiment of a charge and discharge control device;

fig. 2 is a schematic circuit diagram of another embodiment of the charge-discharge control device.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first", "a second", or a third "may explicitly or implicitly include one or more such feature. In the description of the present invention, unless otherwise indicated, the meaning of "a plurality" is two or more.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "connected," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.

Example embodiments will now be described more fully with reference to the accompanying drawings. However, the exemplary embodiments may be embodied in many forms and should not be construed as limited to the examples set forth herein; rather, these example embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the example embodiments to those skilled in the art. The drawings are merely schematic illustrations of the present disclosure and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and thus a repetitive description thereof will be omitted.

The following is a brief description of the technical solution of the embodiments of the present application:

according to some embodiments, as shown in fig. 1 to 2, the present application provides a charge and discharge control device, where the charge and discharge control device includes a control module and at least two serially connected charge and discharge modules, the control module is electrically connected with the at least two serially connected charge and discharge modules respectively, and the charge and discharge modules each include:

the charging and discharging device comprises a charging and discharging switch and a bypass module, wherein a first end of the charging and discharging switch is used for being electrically connected with a negative electrode of a battery V, a second end of the charging and discharging switch and a first end of the bypass module are used for being electrically connected with a negative electrode of a charging power supply or a next charging and discharging module, and a second end of the bypass module is used for being electrically connected with a positive electrode of the battery V and a positive electrode of the charging power supply or a previous charging and discharging module;

the control module is used for detecting electric signals of one or more batteries V, controlling the on-off of one or more charge-discharge switches and controlling the on-off of one or more bypass modules.

The working principle based on the above embodiment is that the control module is used for detecting the electric signals of all the batteries V in at least two serially connected charge and discharge modules. When the control module detects that one of the batteries V is fully charged and the other batteries V are not fully charged during charging, the control module controls a charge-discharge switch corresponding to the fully charged battery V to be disconnected, so that the fully charged battery V stops charging; the control module also controls the corresponding bypass module of the fully charged battery V to close so that the other batteries V that are not fully charged continue to charge. When the control module detects that all batteries V are fully charged, the control module controls all bypass modules and all charge and discharge switches to be disconnected. At this time, all the batteries V in the at least two serially connected charge-discharge modules are fully charged. All bypass modules are disconnected in preparation for the next charge. The method and the device can disconnect the fully charged battery V, and continuously charge the non-fully charged battery V, so that the whole series battery pack reaches a real full-charge state.

Preferred embodiments of the present disclosure are further elaborated below in conjunction with figures 1-2 of the present description.

According to some embodiments, as shown in fig. 1 to 2, the charge-discharge control device further includes a charge master switch, a first end of the charge master switch is electrically connected to the battery anodes of the heads of the at least two serially connected charge-discharge modules, and a second end of the charge master switch is electrically connected to the anode of the charge power supply.

The working principle based on the above embodiment is that, as shown in fig. 1, in some embodiments, the charging master switch adopts a relay S0, one end of a contactor end of the relay S0 is connected with the battery anodes of the heads of at least two serially connected charging and discharging modules, the other end of the contactor end of the relay S0 is used for connecting with the anode of the charging power supply, and a coil end of the relay S0 is used for receiving the control signal 300 of the control module. When the battery needs to be charged, the control module controls the coil end of the relay S0 to be electrified, the relay is attracted, and all the batteries are charged; when all batteries are fully charged, the control module controls the coil end of the relay S0 to lose electricity, the relay is disconnected, and all batteries stop charging.

As shown in fig. 2, in other embodiments, the charging master switch adopts a MOS transistor Q0, a source electrode of the MOS transistor Q0 is connected to the battery anodes of the heads of at least two serially connected charging and discharging modules, and a drain electrode of the MOS transistor Q0 is electrically connected to the anode of the charging power supply. The gate of the MOS transistor Q0 is used for receiving the control signal 300 of the control module. When the battery needs to be charged, the control module outputs a high-level control signal 300 to the grid electrode of the MOS tube Q0, the MOS tube Q0 is conducted, and the battery is charged; when all the batteries are fully charged, the control module outputs a low-level control signal 300 to the grid electrode of the MOS tube Q0, the MOS tube Q0 is cut off, and the batteries stop charging.

In other embodiments, the charging master switch may also use a device with a switching function, such as a triode or a load switch, which is not limited in this application.

Further, according to some embodiments, as shown in fig. 1, the first bypass module includes a first diode D1, where an anode of the first diode D1 and a second end of the first charge-discharge switch are used to be electrically connected to a cathode of a charging power source or to be electrically connected to a next charge-discharge module, and an anode of the first diode D1 is used to be electrically connected to an anode of the battery V and to be electrically connected to an anode of the charging power source or to be electrically connected to a previous charge-discharge module.

The working principle based on the above embodiment is that, as shown in fig. 1, in some embodiments, when the batteries V in at least two charge and discharge modules connected in series are connected in series to a load supply voltage interval, preferably, when the value between the middle value and the upper limit value of the load supply voltage interval is between, then, power is supplied to the load; and detecting and acquiring the total voltage of the batteries connected in series, and when the total voltage of the batteries connected in series is lower than a certain limit value of a load power supply voltage interval, sequentially switching the batteries connected in series with the batteries except the batteries connected in series from low to high according to the sequence of the voltages.

The load power supply voltage interval can be set according to the power supply voltage interval actually required by the load.

When one of the batteries V is needed to supply power to a load, the corresponding charge and discharge switch is closed; when the power supply is not needed, the corresponding charge and discharge switch is turned off, and the load is continuously connected with the negative power supply through the corresponding first diode D1.

Further, according to some embodiments, as shown in fig. 1, the bypass module further includes a bypass switch S1, the bypass switch S1 is connected in parallel with the first diode D1, and the control module controls on-off of the bypass switch S1.

The working principle of the embodiment is that when the control module detects that one of the batteries V is fully charged and the other batteries are not fully charged during charging, the control module controls the charge and discharge switches corresponding to the fully charged batteries V to be disconnected so that the fully charged batteries V stop charging; the control module also controls the bypass switch S1 corresponding to the fully charged battery V to be closed so that the other batteries which are not fully charged continue to be charged. When the control module detects that all batteries are fully charged, the control module controls all the bypass switch S1, the charge and discharge switch and the charge master switch to be disconnected. At this time, all batteries in at least two serially connected charge-discharge modules are fully charged. The method and the device can disconnect the fully charged battery, and charge the battery which is not fully charged continuously, so that the whole series battery pack achieves a real full-charge state.

Further, as shown in fig. 1, in some embodiments, the bypass switch employs a relay S1. In other embodiments, the bypass switch may also use a device with a switching function, such as a triode, which is not limited in this application.

According to some embodiments, as shown in fig. 2, the bypass module employs MOS transistors.

Based on the above embodiments, in some embodiments, the bypass module may employ a switching device formed by a diode and a relay as shown in fig. 1, where the diode is used to supply power to the load uninterruptedly when the relay S1 is controlled to open and close the relay S2 when the battery power is switched. In other embodiments, the MOS transistor shown in fig. 2 may be used, and the parasitic diode is also disposed in the MOS transistor, so that the cost is saved by replacing the diode and the relay with the MOS transistor. Devices with switching functions such as load switches and ideal diodes can also be used, and the application is not limited.

In some embodiments, as shown in fig. 1, the charge-discharge switch employs a relay, and as shown in fig. 1, the charge-discharge switch employs a relay S1. In other embodiments, as shown in fig. 2, the charge-discharge switch is a MOS transistor, and as shown in fig. 2, the charge-discharge switch is a MOS transistor Q1. In other embodiments, the charge-discharge switch may also use a switching device such as a triode or a load switch, which is not limited in this application.

According to some embodiments, as shown in fig. 1, the charge-discharge control device further includes a buffer circuit electrically connected to the battery anodes of the at least two serially connected charge-discharge module heads.

Further, the buffer circuit comprises a resistor and a super capacitor, one end of the resistor is electrically connected with the battery anodes of the heads of the at least two serially-connected charge and discharge modules, the other end of the resistor is electrically connected with the anode of the super capacitor, the cathode of the super capacitor is electrically connected with the battery cathodes of the tails of the at least two serially-connected charge and discharge modules and the cathode of the load, and the other end of the resistor is used for outputting an anode power supply to the anode of the load.

The super capacitor has strong power output performance, can instantly release high current or high power, plays a role of peak clipping and valley filling, can be used as auxiliary energy when the external motor is started or the high power is needed to be instantly compensated in the mechanical operation process of equipment, can work in an environment of-40 ℃, and has decisive advantages under the working condition of low-temperature starting instant high power; meanwhile, the super capacitor can be used for balancing the voltage of each battery unit.

According to some embodiments, as shown in fig. 2, the buffer circuit may employ the following design in addition to the resistor and super capacitor designs:

the buffer circuit comprises an inductor L, one end of the inductor L is electrically connected with the battery anodes of the heads of the at least two serially connected charge and discharge modules, and the other end of the inductor L is used for outputting an anode power supply to the anode of the load.

The working principle based on the embodiment is that the inductance L can store energy, and inductive reactance exists, so that the buffer circuit design of the resistor and the super capacitor can be replaced.

Further, as shown in fig. 2, the buffer circuit further includes a freewheeling diode D0, where a negative electrode of the freewheeling diode D0 is electrically connected to one end of the inductor L, and an anode of the freewheeling diode D0 is electrically connected to a negative electrode of the battery at the tail of the at least two serially connected charge-discharge modules and a negative electrode of the load.

The working principle based on the embodiment is that when at least two serially connected charge and discharge modules are powered off and output, the inductor L freewheels through the freewheeling diode D0 to buffer impact on a circuit in the switching process of the switch.

Further, as shown in fig. 1 and 2, the charge-discharge module further includes a fuse F, and the fuse is connected in series with the battery and the charge-discharge switch.

The fuse F can ensure that the loop can be cut off when the loop is short-circuited, and the safety is ensured.

The fuse F and the corresponding battery V and the corresponding charge-discharge switch can be mutually exchanged, and the functions are not affected. The fuse F, the corresponding battery V and the corresponding charge-discharge switch are connected in series.

According to some embodiments, as shown in fig. 2, the present application provides a charge control method applied to the charge and discharge control device as described above, the charge control method including:

step 101, detecting and acquiring electric signals of all batteries in at least two serially connected charge and discharge modules; the control module calculates an electric quantity signal of the battery according to the electric signal.

102, when the electric signals of all batteries in at least two serially connected charge-discharge modules are lower than a first preset threshold, namely the electric quantity of the batteries is too low, controlling the charge main switch and all charge-discharge switches to be on, and controlling all bypass modules to be off;

step 103, when the electric signal of one of the batteries is charged to reach a second preset threshold, that is, when the battery is fully charged, the charge-discharge switch corresponding to the battery, which controls the electric signal to reach the second preset threshold, is turned off, and the bypass module corresponding to the battery, which controls the electric signal to reach the second preset threshold, is turned on, so that other batteries which are not fully charged can be normally charged;

and 104, when the electric signals of all batteries V in the at least two serially connected charge-discharge modules reach a second preset threshold, namely all batteries are fully charged, controlling the charge main switch to be disconnected and controlling all bypass modules to be disconnected.

The electrical signal may be a voltage signal or a current signal, which is not limited in this application. The first preset threshold value can be set according to actual requirements.

According to some embodiments, as shown in fig. 2, the present application provides a discharge control method, applied to a charge-discharge control device as described above,

in some embodiments, the discharge control method includes:

step 201, acquiring a power supply voltage interval of a load, acquiring electric signals of all batteries in the at least two serially connected charge-discharge modules, calculating to obtain a set number of batteries in the at least two serially connected charge-discharge modules according to an upper limit value of the power supply voltage interval and the electric signals of all batteries, and serially connecting the batteries to the set number according to the order of the electric signals from high to low, and then supplying power to the load;

in some embodiments, the batteries are connected in series to a set number in order of voltage from high to low, and if all the batteries are in a fully charged state, then the batteries at any position may be selected to be connected in series to the set number.

The upper limit value of the power supply voltage interval is the highest voltage which can normally work by the load, and the lower limit value of the power supply voltage interval is the lowest voltage which can normally work by the load. The voltage after the series connection of the set number of batteries is close to the upper limit value of the power supply voltage interval, and the voltage after the series connection of the set number of batteries can be equal to the upper limit value of the power supply voltage interval, but cannot exceed the upper limit value of the power supply voltage interval, so that the load is prevented from being damaged due to overhigh voltage.

Step 202, switching the batteries in the set number from low to high according to the sequence of the electric signals and the batteries outside the set number from high to low according to the sequence of the electric signals;

in some embodiments, the control module controls the batteries in the set number to switch from low to high in order to switch from high to low in order to make the voltages of all the batteries in the at least two serially connected charge and discharge modules close, the voltages of the batteries are not different, and the electric quantity is not different.

And step 203, stopping switching when the electrical signal of the series connection of the batteries with the set number is lower than the electrical signal difference value between the upper limit value of the power supply voltage interval and the battery with the highest voltage among the batteries with the set number, and entering step 201 until the series connection number of the batteries with the set number is all the batteries in the at least two series connection charge and discharge modules.

In some embodiments, when the voltage of the series connection of the set number of batteries is lower than the voltage difference between the upper limit value of the power supply voltage interval and the highest voltage battery among the batteries outside the set number, it is indicated that the highest voltage battery among the batteries outside the set number is connected in series and does not exceed the upper limit value of the power supply voltage interval of the load, so step 201 is entered, such that the set number of batteries is added with 1, and then steps 201 to 203 are cycled until the set number of batteries is all the series connection of batteries.

Further, after step 203, the method further includes:

step 204, when the electrical signal of a single battery in the at least two serially connected charge-discharge modules is lower than a third preset threshold value, disconnecting a charge-discharge switch corresponding to the battery with the electrical signal lower than the third preset threshold value, and connecting a corresponding bypass module;

and 205, when the electric signals of all the batteries in the at least two serially connected charge-discharge modules are lower than the lower limit value of the power supply voltage interval, controlling the at least two serially connected charge-discharge modules to stop supplying power to the load.

The third preset threshold value can be set according to actual requirements. When the voltage of the single battery is lower than the third preset threshold value, the condition that the battery electric quantity is too low is indicated, and the discharge to the load can not be continued, so that the overdischarge is prevented, and the service life of the battery is further prolonged. When the voltage of the remaining battery series connection is lower than the lower limit value of the power supply voltage interval, the voltage of the remaining battery series connection is insufficient to enable the load to work normally, and at the moment, all the charge and discharge switches are required to be controlled to be disconnected, and all the bypass modules are required to be controlled to be disconnected.

To facilitate understanding by those skilled in the art, the following description applies to a specific scenario, and in some embodiments, the discharging method includes:

the upper limit of the load power supply voltage is taken as a control limit 1, and the lower limit of the load power supply voltage is taken as a control limit 2; examples: for a 20V10AH battery pack, the upper limit of the load power supply voltage is 24V, and the corresponding control limit is 1; the undervoltage protection voltage of the load is 18V, which corresponds to the control limit 2.

Detecting and acquiring electric signals of the at least two batteries; examples: the control module detects and acquires a voltage signal of each battery, for example, the voltage of the first battery is 3.99V, and the voltage of the second battery is 3.98V.

Determining the number of batteries which need to be operated in series according to the control limit 1 and the control limit 2; examples: the voltage range of the battery is 1.5V-4V, and the battery pack is composed of 12 batteries in series. When a single battery reaches 4V full power, then any 6 batteries are required to supply power in series. When the voltage of a single battery is 3V, then any 8 batteries are required to be powered in series. And so on.

According to the number of batteries needing to be in series connection, selecting a corresponding number of batteries from all the batteries to supply power to a load after being in series connection, continuously cycling different batteries to enter series connection operation, and keeping the number of the batteries in series connection operation unchanged; examples: when a single battery reaches 4V full power, then any 6 batteries are required to supply power in series. The current battery pack has 12 batteries in total, and the on-off states of the charge-discharge switch and the bypass module are controlled by the control module, so that the fact that only 6 batteries are in a series connection conduction state between the positive electrode and the negative electrode at the same time is ensured. And the batteries connected in series in the switching circuit are periodically circulated through the set switching time, so that the discharging balance of each battery is basically ensured.

When the voltage of the single battery drops to certain limit values, the number of batteries working in series is changed to supply power to the load, and different batteries are continuously circulated to enter the series operation, and meanwhile, the number of the batteries working in series is kept unchanged; examples: when the single battery voltage drops to 3.42V, then a transition is made to 7 battery cycles to switch the series supply. When the single battery voltage drops to 3V, then a transition is made to 8 battery cycles to switch the series supply.

And (3) carrying out load protection and disconnecting the circuit until the total voltage of the series power supply of all the batteries is reduced to the undervoltage protection voltage of the load. Examples: and (3) load protection is performed and the circuit is disconnected until the total voltage of the serial power supply of all 12 batteries is reduced to 18V.

In the initial stage of battery power supply, the electric quantity of the battery is sufficient, so that the voltage signal and the current signal are also sufficient, and the number of batteries connected in series in the initial stage of battery power supply is small. If the voltage required by the load is enough to only need one fully charged battery voltage, only one battery is needed in the initial stage; if the voltage required by the load is enough to connect a plurality of fully charged batteries in series, the number of batteries required to be connected in series needs to be calculated according to the power supply voltage of the load in the early stage. In the later stage of battery power supply, the electric quantity of the batteries is reduced, the voltage signal and the current signal are also reduced, and in order to reach the load power supply voltage, the number of batteries connected in series needs to be increased until the number of batteries connected in series is all batteries connected in series. When the total electric signal after at least two serial charge and discharge modules are connected in series is lower than the control limit 2, namely the electric quantity of all batteries is too low, the load is protected, and the circuit is disconnected.

As shown in fig. 1 and 2, the input signals 201 to 20n+1 are signals input to at least two serial charge and discharge modules by the control module, and the output signals 101 to 10m+1 are signals output to the control module by at least two serial charge and discharge modules.

In the description of the above embodiments, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

While the present disclosure has been described with reference to several exemplary embodiments, it is understood that the terminology used is intended to be in the nature of words of description and illustration rather than of limitation. As the present disclosure may be embodied in several forms without departing from the spirit or essential attributes thereof, it should be understood that the above-described embodiments are not limited by any of the details of the foregoing description, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalences of such metes and bounds are therefore intended to be embraced by the appended claims.

Claims (15)

1. The utility model provides a charge-discharge control device, its characterized in that, charge-discharge control device includes control module and at least two series connection's charge-discharge module, control module electricity respectively is connected two at least series connection's charge-discharge module, charge-discharge module all includes:

the battery charging and discharging device comprises a charging and discharging switch and a bypass module, wherein a first end of the charging and discharging switch is used for being electrically connected with a negative electrode of a battery, a second end of the charging and discharging switch and a first end of the bypass module are used for being electrically connected with a negative electrode of a charging power supply or a next charging and discharging module, and a second end of the bypass module is used for being electrically connected with a positive electrode of the battery and a positive electrode of the charging power supply or a last charging and discharging module;

the control module is used for detecting the electric signals of one or more batteries, controlling the on-off of one or more charge-discharge switches and controlling the on-off of one or more bypass modules.

2. The charge and discharge control device of claim 1, further comprising a charge master switch having a first end electrically connected to the battery anodes of the at least two serially connected charge and discharge module heads and a second end for electrically connecting to the positive electrode of the charging power source.

3. The charge and discharge control device according to claim 2, wherein the bypass module includes a first diode, a positive electrode of the first diode and a second end of the charge and discharge switch are used for electrically connecting a negative electrode of a charging power supply or electrically connecting a next charge and discharge module;

the negative electrode of the first diode is used for being electrically connected with the positive electrode of the battery and the positive electrode of the charging power supply or the last charging and discharging module.

4. The charge-discharge control device according to claim 3, wherein the bypass module further comprises a bypass switch connected in parallel with the first diode, and the control module controls the bypass switch to be turned on and off.

5. The charge and discharge control device according to claim 4, wherein the bypass switch is a relay or a triode.

6. The charge and discharge control device according to claim 2, wherein the bypass module employs a MOSFET or a load switch or a relay or an ideal diode.

7. The charge-discharge control device according to claim 2, wherein the charge-discharge switch is a relay or MOSFET or triode or load switch.

8. The charge-discharge control device according to claim 2, wherein the charge-discharge module further comprises a fuse connected in series with the battery and the charge-discharge switch.

9. The charge-discharge control device according to claim 2, further comprising a buffer circuit, wherein the buffer circuit comprises a resistor and a super capacitor, one end of the resistor is electrically connected with the battery anodes of the heads of the at least two serially connected charge-discharge modules, the other end of the resistor is electrically connected with the anode of the super capacitor, the cathode of the super capacitor is electrically connected with the battery cathodes of the tails of the at least two serially connected charge-discharge modules and the cathode of the load, and the other end of the resistor is used for outputting an anode power supply to the anode of the load.

10. The charge-discharge control device according to claim 2, further comprising a snubber circuit including an inductor, one end of the inductor being electrically connected to the battery anodes of the at least two serially connected charge-discharge module heads, the other end of the inductor being configured to output an anode power supply to the anode of the load.

11. The charge and discharge control device of claim 10, wherein the buffer circuit further comprises a freewheeling diode having a negative electrode electrically connected to one end of the inductor, and a positive electrode of the freewheeling diode is configured to electrically connect a negative electrode of the battery at the tail of the at least two serially connected charge and discharge modules and a negative electrode of the load.

12. The charge-discharge control device according to claim 2, wherein the charge master switch is a relay or a triode or a MOSFET or a load switch.

13. A charge control method, characterized by being applied to the charge-discharge control apparatus according to any one of claims 2 to 12, comprising:

step 101, detecting and acquiring electric signals of all batteries in at least two serially connected charge and discharge modules;

102, when the electric signals of all batteries in at least two serially connected charge-discharge modules are lower than a first preset threshold value, controlling the charge main switch and all charge-discharge switches to be turned on and controlling all bypass modules to be turned off;

step 103, when the electric signal charge of one of the batteries reaches a second preset threshold, the charge-discharge switch corresponding to the battery which controls the electric signal to reach the second preset threshold is turned off, and the bypass module corresponding to the battery which controls the electric signal to reach the second preset threshold is turned on;

and 104, when the electric signals of all batteries in the at least two serially connected charge and discharge modules reach a second preset threshold value, controlling the charge main switch to be disconnected and controlling all bypass modules to be disconnected.

14. A discharge control method, characterized by being applied to the charge-discharge control apparatus according to any one of claims 1 to 12, comprising:

step 201, acquiring a power supply voltage interval of a load, acquiring electric signals of all batteries in the at least two serially connected charge-discharge modules, calculating to obtain a set number of batteries in the at least two serially connected charge-discharge modules according to an upper limit value of the power supply voltage interval and the electric signals of all batteries, and serially connecting the batteries to the set number according to the order of the electric signals from high to low, and then supplying power to the load;

step 202, switching the batteries in the set number from low to high according to the sequence of the electric signals and the batteries outside the set number from high to low according to the sequence of the electric signals;

and step 203, stopping switching when the electrical signal of the series connection of the batteries with the set number is lower than the electrical signal difference value between the upper limit value of the power supply voltage interval and the battery with the highest voltage among the batteries with the set number, and entering step 201 until the series connection number of the batteries with the set number is all the batteries in the at least two series connection charge and discharge modules.

15. The discharge method of claim 14, wherein after step 203, the method further comprises:

step 204, when the electrical signal of a single battery in the at least two serially connected charge-discharge modules is lower than a third preset threshold value, disconnecting a charge-discharge switch corresponding to the battery with the electrical signal lower than the third preset threshold value, and connecting a corresponding bypass module;

and 205, when the electric signals of all the batteries in the at least two serially connected charge-discharge modules are lower than the lower limit value of the power supply voltage interval, controlling the at least two serially connected charge-discharge modules to stop supplying power to the load.